Ethernet module

ABSTRACT

In a network device, a connector module comprises a network connector coupled to the connector module in a configuration that transfers power and communication signals and an application connector that comprises serial media independent interface (SMII) pins and power pins. A Power-over-Ethernet (PoE) circuit is coupled between the network connector and the application connector.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to as acontinuation-in-part and incorporates herein by reference in itsentirety for all purposes U.S. patent application Ser. No. 11/207,601entitled “SYSTEMS AND METHODS OPERABLE TO ALLOW LOOP POWERING OFNETWORKED DEVICES,” by John R. Camagna, Sajol Ghoshal and FrancoisCrepin, filed Aug. 19, 2005; U.S. patent application Ser. No. 11/287,408entitled METHOD FOR HIGH VOLTAGE POWER FEED ON DIFFERNTIAL CABLE PAIRSFROM A NETWORK,” by John R. Camagna, Philip Crawley, and Sajol Ghoshal,filed Nov. 23, 2005; and U.S. patent application Ser. No. 11/445,084entitled “ETHERNET MODULE,” by Sajol Ghoshal and John R. Camagna, filedMay 31, 2006.

BACKGROUND

Many networks such as local and wide area networks (LAN/WAN) structuresare used to carry and distribute data communication signals betweendevices. Various network elements include hubs, switches, routers, andbridges, peripheral devices, such as, but not limited to, printers, dataservers, desktop personal computers (PCs), portable PCs and personaldata assistants (PDAs) equipped with network interface cards. Devicesthat connect to the network structure use power to enable operation.Power of the devices may be supplied by either an internal or anexternal power supply such as batteries or an AC power via a connectionto an electrical outlet.

Some network solutions can distribute power over the network incombination with data communications. Power distribution over a networkconsolidates power and data communications over a single networkconnection to reduce installation costs, ensures power to networkelements in the event of a traditional power failure, and enablesreduction in the number of power cables, AC to DC adapters, and/or ACpower supplies which may create fire and physical hazards. Additionally,power distributed over a network such as an Ethernet network mayfunction as an uninterruptible power supply (UPS) to components ordevices that normally would be powered using a dedicated UPS.

Additionally, network appliances, for examplevoice-over-Internet-Protocol (VOIP) telephones and other devices, areincreasingly deployed and consume power. When compared to traditionalcounterparts, network appliances use an additional power feed. Onedrawback of VOIP telephony is that in the event of a power failure theability to contact emergency services via an independently poweredtelephone is removed. The ability to distribute power to networkappliances or circuits enable network appliances such as a VOIPtelephone to operate in a fashion similar to ordinary analog telephonenetworks currently in use.

Distribution of power over Ethernet (PoE) network connections is in partgoverned by the Institute of Electrical and Electronics Engineers (IEEE)Standard 802.3 and other relevant standards, standards that areincorporated herein by reference. However, power distribution schemeswithin a network environment typically employ cumbersome, real estateintensive, magnetic transformers. Additionally, power-over-Ethernet(PoE) specifications under the IEEE 802.3 standard are stringent andoften limit allowable power.

Many limitations are associated with use of magnetic transformers.Transformer core saturation can limit current that can be sent to apower device, possibly further limiting communication channelperformance. Cost and board space associated with the transformercomprise approximately 10 percent of printed circuit board (PCB) spacewithin a modern switch. Additionally, failures associated withtransformers often account for a significant number of field returns.Magnetic fields associated with the transformers can result in lowerelectromagnetic interference (EMI) performance.

However, magnetic transformers also perform several important functionssuch as supplying DC isolation and signal transfer in network systems.Thus, an improved approach to distributing power in a networkenvironment may be sought that addresses limitations imposed by magnetictransformers while maintaining transformer benefits.

SUMMARY

According to an embodiment of a network device, a connector modulecomprises a network connector coupled to the connector module in aconfiguration that transfers power and communication signals and anapplication connector that comprises serial media independent interface(SMII) pins and power pins. A Power-over-Ethernet (PoE) circuit iscoupled between the network connector and the application connector.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention relating to both structure and method ofoperation may best be understood by referring to the followingdescription and accompanying drawings:

FIGS. 1A and 1B are schematic block diagrams that respectivelyillustrate a high level example embodiments of client devices in whichpower is supplied separately to network attached client devices, and aswitch that is a power supply equipment (PSE)-capable power-overEthernet (PoE) enabled LAN switch that supplies both data and powersignals to the client devices;

FIG. 2 is a functional block diagram illustrating a network interfaceincluding a network powered device (PD) interface and a network powersupply equipment (PSE) interface, each implementing a non-magnetictransformer and choke circuitry;

FIG. 3 is a schematic block and circuit diagram depicting an embodimentof a network device in the form of a connector module that is highlysuitable for usage in supplying a power feed on multiple pairs;

FIG. 4A is a schematic block and circuit diagram showing an embodimentof a network device configured as a connector module with a non-magnetictransformer that enables an integrated single-chip implementation;

FIG. 4B is a schematic block and circuit diagram illustrating anembodiment of a network device configured as a connector module thatincludes a T-Less Connect™ solid-state transformer;

FIG. 5 is a schematic circuit and block diagram depicting an embodimentof a network device configured as a connector module for usage withpower sourcing equipment (PSE);

FIG. 6 is a schematic circuit and block diagram showing an embodiment ofa network device configured as a connector module for usage with anintegrated power sourcing equipment (iPSE) that implements anon-magnetic transformer;

FIG. 7 is a schematic circuit and block diagram that depicts anembodiment of a network device configured for usage as a midspan powersourcing equipment (PSE) connector module;

FIGS. 8A, 8B, and 8C are schematic circuit and block diagramsillustrating embodiments of a network device in configurations ofnetwork attached appliances;

FIGS. 9A, 9B, and 9C are schematic circuit and block diagrams showingembodiments of network devices in configurations of power sourcingequipment (PSE) switch modules;

FIGS. 10A and 10B are schematic circuit and block diagrams illustratingembodiments of a network device arranged as a network interface module;

FIG. 11 (IDF1 FIG. 6) is a schematic block diagram showing an embodimentof a powered network device, for example an enterprise VoIP phone; and

FIG. 12 (IDF16 FIG. 6B) is a schematic block diagram showing anembodiment of a.

DETAILED DESCRIPTION

In various embodiments, an Ethernet module can support a power feed onmultiple signal pairs. Some embodiments can be in the form of aconnector, such as a Registered Jack (RJ)-45 connector, which include anintegrated powered device/power sourcing equipment (PD/PSE) controller,a DC-DC controller for a PD implementation, and an Ethernet transformer.Other embodiments can be in the form of a connector, such as aRegistered Jack (RJ)-45 connector, which include an integrated powereddevice/power sourcing equipment (PD/PSE) controller, a DC-DC controllerfor a PD implementation, and a solid-state transformer, such as aT-connect or T-Less Connect™ solid-state transformer.

Configurations can be implemented which include or exclude an EthernetPhysical Layer (PHY). Configurations can be implemented which include orexclude isolation.

The various modules and structures can be configured with any suitablefootprint. In an illustrative embodiment, a standard footprint can bedefined to specify an interface size of twenty (20) pins including, forexample, eight (8) input RJ-45 pins, six (6) serial media independentinterface (SMII) pins including reference clock signal pins, four (4)Management Data Input/Output (MDIO) pins which include two pins foropto-coupling, and two (2) power pins. MDIO is a standard-driven,dedicated-bus arrangement specified in Institute of Electrical andElectronics Engineers (IEEE) RFC802.3. The MDIO interface is implementedby two pins, and MDIO pin and a Management Data Clock (MDC) pin. MDIO isdefined in relation to access and modification of registers withinphysical layer (PHY) devices, and to connection to media accesscontrollers (MACs) in Ethernet systems. A smaller footprint can bedefined or configured which can eliminate the two reference clock pinsof the SMII interface and/or the two opto-coupling pins of the MDIO.

Referring to FIG. 3, a schematic block and circuit diagram illustratesan embodiment of a network device 300 in the form of a connector module302 that is highly suitable for usage in supplying a power feed onmultiple pairs. The connector module 302 comprises a network connector304 that transfers power and communication signals and an applicationconnector 306 arranged to include serial media independent interface(SMII) pins 308 and power pins 310. The connector module 302 furthercomprises a Power-over-Ethernet (PoE) circuit 312 coupled between thenetwork connector 304 and the application connector 306.

In a particular embodiment, the network connector 304 can be aneight-pin Registered Jack (RJ) 45 physical interface. The applicationconnector 306 can be an arrangement that includes the SMII signalinterface 308, a Management Data Input/Output (MDIO) interface 314, anda two-pin power interface 310. In various configurations, the SMIIsignal interface 308 can be a four-pin signal interface or can be asix-pin interface including both signal pins and reference pins. TheMDIO interface 314, if included in the connector module 302, can beeither a two-pin interface including data and clock lines or a four-pininterface with data, clock or strobe, and opto-coupling lines.

The network device embodiment 300 shown in FIG. 3, the Ethernet PHY 318is connected to the application interface 306 by a SMII interface 308and a Management Data Input/Output (MDIO) interface 314 which incombination make up a non-isolated interface.

In the illustrative network device 300, the Power-over-Ethernet (PoE)circuit 312 comprises a magnetic transformer 316, an Ethernet physicallayer (PHY) 318, a Powered Ethernet Device (PD) controller 320, and aDirect Current-Direct Current (DC-DC) power converter 322. The magnetictransformer 316 connects to communication signal pins 304S of thenetwork interface 304. The Ethernet physical layer (PHY) 318 isconnected between the magnetic transformer 316 and the applicationinterface 306 and is coupled to the application interface 306 by a SMIIinterface 308. The Powered Ethernet Device (PD) controller 320 isconnected to power pins 304P of the network interface 304. In an examplearrangement, the Powered Ethernet Device (PD) controller 320 cancomprise a power switch circuit 326 and a signature and classificationcircuit 328. The Direct Current-Direct Current (DC-DC) power converter322 in connected between the PD controller 320 and power pins 310 of theapplication interface 306.

The illustrative configuration whereby the transformer 316, PDcontroller 320, and the Ethernet PHY 318 are contained within theconnector module 302, and the Ethernet PHY 318 couples to theapplication connector 306 via the SMII interface 310 enables a compactconnector module 302 with reduced pin count by exploiting the internaltransformer 316 to supply power out and the PD controller 320 togenerate a supply voltage, such as 48 volts. Combining the PD controller320 and transformer 316 inside the connector module 302 enablesoperation switching to take place internal to the module withoutreserving pins for passing control signals.

Some arrangements of the Power-over-Ethernet (PoE) circuit 312 caninclude a diode bridge 324 connected between power pins 304P of thenetwork interface 304 and the PD controller 320. The diode bridge 324can be integrated enabling implementation of the module components in acompact package, or even a single-chip package.

The particular connector module 302 can be constructed as an RJ-45connector with a transformer-based 10/100 Powered Ethernet (PD) devicewith an application interface 306 including SMII and power pins. TheRJ-45 connector has eight pins arranged in four pairs.

Referring to FIG. 4A, a schematic block and circuit diagram illustratesan embodiment of a network device 400 configured as a connector module402 with a non-magnetic transformer. The non-magnetic transformer can beintegrated so that the module components can be implemented, if desired,in an integrated, single-chip arrangement. The connector module 402comprises a Power-over-Ethernet (PoE) circuit 412 coupled between anetwork connector 404 and an application connector 406. The illustrativePower-over-Ethernet (PoE) circuit 412 comprises a non-magnetictransformer and choke circuit 416, an Ethernet physical layer (PHY) 418,a Powered Ethernet Device (PD) controller 420, and a DirectCurrent-Direct Current (DC-DC) power converter 422. The non-magnetictransformer and choke circuit 416 is integrated into the iPED 430 andconnected to communication signal pins 404S of the network interface404. The Ethernet physical layer (PHY) 418 is integrated into the iPED430 and connected between the non-magnetic transformer and choke circuit416 and the application interface 406. The illustrative Ethernet PHY 418is connected to the application interface 406 by a SMII interface 408and a Management Data Input/Output (MDIO) interface 414. The PoweredEthernet Device (PD) controller 420 is integrated into the iPED 430 andconnected to power pins 404P of the network interface 404. The DirectCurrent-Direct Current (DC-DC) power converter 422 is integrated intothe iPED 430 and connected between the PD controller 420 and power pins410 of the application interface 406.

The Powered Ethernet Device (PD) controller 420 is depicted as anintegrated device integrated into the IPED 430 and further comprisingintegrated circuit elements including a diode bridge 424 connected topower pins 404P of the network interface 404, a power switch circuit 426connected to the diode bridge 424, and a signature and classificationcircuit 428 connected to the diode bridge 424 and the power switchcircuit 426. The particular connector module 342 can be constructed asan RJ-45 connector with a transformer-less based 10/100 Powered Ethernet(PD) device with an application interface 306 including SMII and powerpins.

Referring to FIG. 4B, a schematic block and circuit diagram illustratesan embodiment of a network device 400 configured as a connector module402 that includes a T-Less Connect™ solid-state transformer 432. Theintegrated Powered Ethernet Device (iPED) 430 can be implemented toincorporate a T-Less Connect™ solid-state transformer 432 that separatesEthernet signals from power signals. The T-Less Connect™ solid-statetransformer 432 can separate the signal and power signals by floatingground potential of the Ethernet PHY relative to earth ground. TheT-Less Connect™ transformer 432 is described more fully in thediscussion of FIG. 2.

Referring to FIG. 5, a schematic circuit and block diagram depicts anembodiment of a network device 500 configured as a connector module 502for usage with power sourcing equipment (PSE). The connector module 502comprises an application connector 506 and a network connector 504coupled by a Power-over-Ethernet (PoE) circuit 512. The illustrativePower-over-Ethernet (PoE) circuit 512 comprises a magnetic transformer516, an Ethernet physical layer (PHY) 518, and a Power SourcingEquipment (PSE) controller 520. The magnetic transformer 516 isconnected to communication signal pins 504S of the network interface504. The Ethernet physical layer (PHY) 518 is connected between themagnetic transformer 516 and the application interface 506. The EthernetPHY 518 is connected to the application interface 506 by a SMIIinterface 508 and a Management Data Input/Output (MDIO) interface 514.The Power Sourcing Equipment (PSE) controller 520 is connected betweenpower pins 504P of the network interface 504 and power feed pins 510 ofthe application interface 506.

In some embodiments, a multi-port switch 536 can be connected to theapplication interface 506, for example on the exterior side of theapplication interface 506 with respect to the connector module 502 sothat the multi-port switch 536 is coupled to the PoE circuit 512 via theapplication interface 506.

The depicted connector module 502 is configured as a RJ-45 PSE moduleincluding the Ethernet PHY 518.

Referring to FIG. 6, a schematic circuit and block diagram depicts anembodiment of a network device 600 configured as a connector module 602for usage with an integrated power sourcing equipment (iPSE) thatimplements a non-magnetic transformer and facilitates an integratedsingle-chip implementation. A power sourcing equipment module 602 has anisolated interface. The connector module 602 comprises an applicationconnector 606 and a network connector 504 coupled by aPower-over-Ethernet (PoE) circuit 612. The Power-over-Ethernet (PoE)circuit 612 has an integrated Powered Ethernet Source (iPES) 630 thatcomprises a non-magnetic power supply circuit 616, an Ethernet physicallayer (PHY) 618, and a Power Sourcing Equipment (PSE) controller 620.The non-magnetic power supply circuit 616 is integrated into the iPES630 and is connected to communication signal pins 604S and power pins604P of the network interface 604. The Ethernet physical layer (PHY) 618is integrated into the iPES 630 and connected between the non-magneticpower supply circuit 616 and the application interface 606. The EthernetPHY 618 is connected to the application interface 606 by a SMIIinterface 608 and a Management Data Input/Output (MDIO) interface 614.The SMII standard specifies support for either direct current (DC) oralternating current (AC) operation. The Power Sourcing Equipment (PSE)controller 620 is connected between the non-magnetic power supplycircuit 616 and power feed pins 610 of the application interface 606.

In the illustrative connector module 602, the iPES 630 is isolated fromapplication resources by isolation capacitors 638 that are connectedbetween the Ethernet PHY 618 and the application interface 606 and oneor more optical couplers 640 connected between the PSE controller 620and the application interface 606. For example, in an AC implementation,suitable isolation capacitors 638 may be 0.01 μF or any suitablecapacitance to supply power supply isolation. Isolation for the MDIO canbe supplied by any suitable component such as capacitors oropto-couplers.

In some embodiments, a multi-port switch 636 can be connected to theapplication interface 606, for example on the exterior side of theapplication interface 606 with respect to the connector module 602 sothat the multi-port switch 636 is coupled to the PoE circuit 612 via theapplication interface 606.

Referring to FIG. 7, a schematic circuit and block diagram depicts anembodiment of a network device 700 configured for usage as a midspanpower sourcing equipment (PSE) connector module 702. The midspanarrangement 702 can be implemented including a network connector 704,such as an RJ-45 connector, with four pairs. The signal can be carriedon two pairs and power carried on the other two pairs. The midspanarrangement is a single package that has input connections to a switchsupplying an Ethernet signal and to power supplied from exterior to theconnector. The midspan connector 702 supplies output power and signallines.

Typically, the midspan can be configured as a power injector that linksbasic Ethernet switches to the end power device. A midspan is typicallyused to deploy installations of powered terminals such as Wireless LocalArea Network (WLAN) access points, network security cameras and InternetProtocol (IP) phones.

One of the limitations of a conventional midspan arrangement is handlingof power and signal in high-speed Ethernet applications. For example, intypical 10/100 Ethernet signal can be placed on two of four pairs andpower placed on the remaining two pairs. However, in gigabit Ethernet,all four pairs carry signal so no lines are available for carryingpower. Accordingly, conventional midspans cannot easily handle power andsignal for gigabit Ethernet.

In contrast, the various connector arrangements disclosed herein enableefficient usage of Ethernet pathways even for gigabit Ethernet. Themidspan connector 702 can include signal conditioning functionalelements, for example that filter the communication signals and separatesignal and power with little or no signal interference. Signals aredistributed using a multi-port switch 736.

The midspan Power Sourcing Equipment (PSE) module 702 comprises aPower-over-Ethernet (PoE) circuit 712 connected between a networkconnector 704 and an application connector 706. The Power-over-Ethernet(PoE) circuit comprises a non-magnetic power supply circuit 716 and aPower Sourcing Equipment (PSE) controller 720. The non-magnetic powersupply circuit 716 is integrated into the midspan PSE module 702 andconnected between the network connector 704 and the applicationconnector 706. A Power Sourcing Equipment (PSE) controller 720 isconnected between the non-magnetic power supply circuit 716 and powerfeed pins 710 of the application interface 706.

In some embodiments, a multi-port switch 736 can be connected to theapplication interface 706 so that the multi-port switch 736 is coupledto the PoE circuit 712 via the application interface 706.

The application connector 706 can be capacitively-coupled to themulti-port switch 736. In various embodiments, the multi-port switch 736may be internal or external to the midspan connector 702.

Referring to FIG. 8A, a schematic circuit and block diagram depicts anembodiment of a network device 800A in the configuration of a networkattached appliance 850. The network attached appliance 850 is an exampleimplementation that incorporates a connector module 802. Theillustrative network attached appliance 850 comprises a housing 852 andan application processor 854 contained within the housing 852. Aconnector module 802 is contained within the housing 852 and configuredto connect the application processor 854 to a network 856. The connectormodule 802 comprises a network connector 804, an application connector806, and a Power-over-Ethernet (PoE) circuit 812. The network connector804 is coupled to the connector module 802 in a configuration thattransfers power and communication signals. The application connector 806is coupled to the connector module 802 and has serial media independentinterface (SMII) pins 808 and power pins 810. The Power-over-Ethernet(PoE) circuit 812 is connected between the network connector 804 and theapplication connector 806.

In the illustrative embodiment, the Power-over-Ethernet (PoE) circuit812 includes an integrated Powered Ethernet Device (iPED) 832. Theintegrated Powered Ethernet Device (iPED) 832 comprises a non-magnetictransformer and choke circuit 816, an Ethernet physical layer (PHY) 818,a Powered Ethernet Device (PD) controller 820, and a DirectCurrent-Direct Current (DC-DC) power converter 822. The non-magnetictransformer and choke circuit 816 is integrated into the iPED 832 andconnected to communication signal pins 804S of the network interface804. The Ethernet physical layer (PHY) 818 is integrated into the iPED832 and connected between the non-magnetic transformer and choke circuit816 and the application interface 806. The Ethernet PHY 818 is connectedto the application interface 806 by a SMII interface 808 and aManagement Data Input/Output (MDIO) interface 814. The Powered EthernetDevice (PD) controller 820 is integrated into the iPED 832 and connectedto power pins 804P of the network interface 804. The DirectCurrent-Direct Current (DC-DC) power converter 822 is integrated intothe iPED 832 and connected between the PD controller 820 and power pins804P of the application interface 804.

Referring to FIG. 8B, a schematic circuit and block diagram depicts anembodiment of a network device 800B in the configuration of a networkattached appliance 850. The network attached appliance 850 is an exampleimplementation that incorporates a connector module 802. Theillustrative network attached appliance 850 comprises a housing 852 andan application processor 854 contained within the housing 852. Aconnector module 802 is contained within the housing 852 and configuredto connect the application processor 854 to a network 856. The connectormodule 802 comprises a network connector 804, an application connector806, and a Power-over-Ethernet (PoE) circuit 812. The network connector804 is coupled to the connector module 802 in a configuration thattransfers power and communication signals. The application connector 806is coupled to the connector module 802 and configured for coupling tothe application processor 854. The Power-over-Ethernet (PoE) circuit 812is coupled between the network connector 804 and the applicationconnector 806.

In the illustrative embodiment, the Power-over-Ethernet (PoE) circuit812 includes an integrated Powered Ethernet Device (iPED) 832. Theintegrated Powered Ethernet Device (iPED) 832 comprises a non-magnetictransformer and choke circuit 816, a Powered Ethernet Device (PD)controller 820, and a Direct Current-Direct Current (DC-DC) powerconverter 822. The non-magnetic transformer and choke circuit 816 isintegrated into the iPED 832 and coupled between communication signalpins 804S of the network interface 804 and the application interface804. The Powered Ethernet Device (PD) controller 820 is integrated intothe iPED 832 and connected to power pins 804P of the network interface804. The Direct Current-Direct Current (DC-DC) power converter 822 isintegrated into the iPED 832 and connected between the PD controller 820and power pins 804P of the application interface 804.

In the illustrative embodiment, the connector module 802 furthercomprises isolation capacitors 838 and at least one optical coupler 840.The isolation capacitors 838 are coupled between the non-magnetictransformer and choke circuit 816 and the application interface 806. Theoptical coupler 840 is connected between the Powered Ethernet Device(PD) 820 and the application interface 806.

The network attached appliance 850 can further comprise an Ethernetphysical layer (PHY) 818 coupled between the application interface 806and the application processor 854. The Ethernet PHY 818 is coupled tothe application processor 854 by a SMII interface 808 and a ManagementData Input/Output (MDIO) interface 814.

Referring to FIG. 8C, a schematic circuit and block diagram depicts anembodiment of a network device 800C in the configuration of a networkattached appliance 850 incorporating a connector module 802 with aPower-over-Ethernet (PoE) circuit 812. In the illustrative embodiment,the Power-over-Ethernet (PoE) circuit 812 includes an integrated PoweredEthernet Device (iPED) 832. The integrated Powered Ethernet Device(iPED) 832 comprises an isolated Ethernet physical layer (PHY) 818C, aPowered Ethernet Device (PD) controller 820, and an isolated DirectCurrent-Direct Current (DC-DC) power converter 822C. The isolatedEthernet physical layer (PHY) 818C is integrated into the iPED 832 andcoupled to the application interface 806 by a SMII interface 808 and aManagement Data Input/Output (MDIO) interface 814. The Powered EthernetDevice (PD) controller 820 is integrated into the iPED 832 and connectedto power pins 804P of the network interface 804. The isolated DirectCurrent-Direct Current (DC-DC) power converter 822 is integrated intothe iPED 832 and connected between the PD controller 820 and power pins804P of the application interface 806.

In some embodiments, the integrated Powered Ethernet Device (iPED) 832can further comprise an autotransformer 816C that is integrated into theiPED 832 and coupled between communication signal pins of the networkinterface 804 and the application interface 806. Isolation capacitorscan be coupled to the autotransformer 816C and integrated into the iPED832 coupled between communication signal pins of the network interface804 and the application interface 806.

The isolated Ethernet physical layer (PHY) 818C can have internalisolation, for example by including isolation capacitors 838 coupled tothe SMII interface 808 and the MDIO interface 814.

An isolation barrier is formed by isolating components and/or devices inthe isolated Ethernet physical layer (PHY) 818C the isolated DirectCurrent-Direct Current (DC-DC) power converter 822C, thereby isolatingthe network interface 804 from the application interface 806.

Referring to FIG. 9A, a schematic circuit and block diagram depicts anembodiment of a network device 900 in the configuration of a powersourcing equipment (PSE) switch module 950. The PSE switch module 950may be termed a power sourcing equipment appliance and can comprise ahousing 952 and an Ethernet switch 958 and an isolated power supplycontained within the housing 952. The PSE switch module 950 furthercomprises a connector module 902 contained within the housing 952 andconfigured to couple the Ethernet switch 958 and the isolated powersupply 960 to a network 956. The connector module comprises a networkconnector 904, an application connector 906, and a Power-over-Ethernet(PoE) circuit 912. The network connector 904 is connected to theconnector module 902 in a configuration that transfers power andcommunication signals. The application connector 906 is connected to theconnector module 902 and comprises serial media independent interface(SMII) pins 908 and power pins 910. The Power-over-Ethernet (PoE)circuit 912 is connected between the network connector 904 and theapplication connector 906.

In the illustrative embodiment, the Power-over-Ethernet (PoE) circuit912 can include an integrated Powered Ethernet Source (iPES) 930. Theintegrated Powered Ethernet Source (iPES) 930 comprises a non-magnetictransformer and choke circuit 912, an Ethernet physical layer (PHY) 918,and a Power Sourcing Equipment (PSE) controller 920. The non-magnetictransformer and choke circuit 912 is integrated into the iPES 930 and isconnected to communication signal pins 904S and power pins 904P of thenetwork interface 904. The Ethernet physical layer (PHY) 918 isintegrated into the iPES 930 and connected between the non-magnetictransformer and choke circuit 916 and the application interface 906. TheEthernet PHY 918 is connected to the application interface 906 by a SMIIinterface 908 and a Management Data Input/Output (MDIO) interface 914.The Power Sourcing Equipment (PSE) controller 920 is connected betweenthe non-magnetic transformer and choke circuit 916 and power feed pins910 of the application interface 906.

In the illustrative PSE switch module 950, the iPES 930 is isolated fromthe Ethernet switch 958 and the isolated power supply 960 by isolationcapacitors 938 that are connected between the Ethernet PHY 918 and theapplication interface 906 and one or more optical couplers 940 connectedbetween the PSE controller 920 and the application interface 906.

Referring to FIG. 9B, a schematic circuit and block diagram depicts anembodiment of a network device 900 in the configuration of a powersourcing equipment (PSE) switch module 970 or power sourcing equipmentappliance with an Ethernet physical layer (PHY) 918 exterior to anintegrated Powered Ethernet Source (iPES) 930. The power sourcingequipment appliance 970 comprises the Ethernet physical layer (PHY) 981coupling an Ethernet switch 958 and an isolated power supply 960 to anapplication interface 906. The Power-over-Ethernet (PoE) circuit 912comprises an integrated Powered Ethernet Source (iPES) 930 and a PowerSourcing Equipment (PSE) controller 920. The integrated Powered EthernetSource (iPES) 930 comprises a non-magnetic transformer and choke circuit916 integrated into the iPES 930 and connected to communication signalpins 904S and power pins 904P of the network interface 904. The PowerSourcing Equipment (PSE) controller 920 is connected between thenon-magnetic transformer and choke circuit 916 and power feed pins 910of the application interface 906.

The iPES 930 can be isolated from the Ethernet switch 958 and theisolated power supply 960 by isolation capacitors 938 that are connectedbetween the Ethernet PHY 918 and the application interface 906 and oneor more optical couplers 940 connected between the PSE controller 920and the application interface 906.

PSE switch modules 950 and 970 in FIGS. 9A and 9B respectively showexample isolation structures.

Referring to FIG. 9C, a schematic circuit and block diagram depicts anembodiment of a network device 900C in the configuration of a powersourcing equipment (PSE) switch module 950. The PSE switch module 950may be termed a power sourcing equipment appliance and can comprise ahousing 952 and an Ethernet switch 958 and an isolated power supplycontained within the housing 952. The PSE switch module 950 furthercomprises a connector module 902 contained within the housing 952 andconfigured to couple the Ethernet switch 958 and the isolated powersupply 960 to a network 956. The connector module comprises a networkconnector 904, an application connector 906, and a Power-over-Ethernet(PoE) circuit 912. The network connector 904 is connected to theconnector module 902 in a configuration that transfers power andcommunication signals. The application connector 906 is connected to theconnector module 902 and comprises serial media independent interface(SMII) pins 908 and power pins 910. The Power-over-Ethernet (PoE)circuit 912 is connected between the network connector 904 and theapplication connector 906.

In the illustrative embodiment, the Power-over-Ethernet (PoE) circuit912 can include an integrated Powered Ethernet Source (iPES) 930. Theintegrated Powered Ethernet Source (iPES) 930 comprises an isolatedEthernet physical layer (PHY) 918C, and a Power Sourcing Equipment (PSE)controller 920. The isolated Ethernet physical layer (PHY) 918C isintegrated into the iPES 930 and connected to the application interface906 by a SMII interface 908 and a Management Data Input/Output (MDIO)interface 914. The Power Sourcing Equipment (PSE) controller 920 is topower feed pins 910 of the application interface 906.

In some embodiments, the integrated Powered Ethernet Source (iPES) 930can further comprise an autotransformer 916C that is integrated into theiPES 930 and coupled between communication signal pins of the networkinterface 904 and the application interface 906. Isolation capacitorscan be coupled to the autotransformer 916C and integrated into the iPES930 coupled between communication signal pins of the network interface904 and the application interface 906.

The isolated Ethernet physical layer (PHY) 918C can have internalisolation, for example by including isolation capacitors 938 coupled tothe SMII interface 908 and the MDIO interface 914.

A Buck converter 962 can be integrated into the integrated PoweredEthernet Source (iPES) 930 and coupled to a power line supplying theisolated Ethernet physical layer (PHY) 918C from the isolated powersupply 960.

An isolation barrier is formed by isolating components and/or devices inthe isolated Ethernet physical layer (PHY) 918C, thereby isolating thenetwork interface 904 from the application interface 906.

Referring to FIG. 10A, a schematic circuit and block diagram illustratesan embodiment of a network device 1000A arranged as a network interfacemodule 1002. The network interface module 1002 comprises a networkconnector 1004 connected to the network interface module 1002 in aconfiguration that transfers power and communication signals and anapplication connector 1006. A Power-over-Ethernet (PoE) circuit 1012 isconnected between the network connector 1004 and the applicationconnector 1006. The PoE circuit 1012 comprises a transformer 1016connected to communication signal pins 1004S of the network interface1004 and an Ethernet physical layer (PHY) 1018 connected between thetransformer 1016 and the application interface 1006. ThePower-over-Ethernet (PoE) circuit 1012 can further comprise a PoweredEthernet Device (PD) controller 1020 coupled to power pins 1004P of thenetwork interface 1004, and a Direct Current-Direct Current (DC-DC)power converter 1022 connected between the PD controller 1020 and powerpins 1010 of the application interface 1006.

The illustrative network interface module 1002 is depicted as a powereddevice module. In a different application, the network interface modulecan be configured for usage as a power sourcing equipment interfacemodule, for example in an implementation such as that shown in FIG. 5where a Power-over-Ethernet (PoE) circuit can comprise a Power SourcingEquipment (PSE) controller coupled between power pins of the networkinterface and power feed pins of the application interface.

Referring to FIG. 10B, a schematic circuit and block diagram illustratesan embodiment of a network device 1000B arranged as a network interfacemodule 1002. The network interface module 1002 comprises a networkconnector 1004 connected to the network interface module 1002 in aconfiguration that transfers power and communication signals and anapplication connector 1006. A Power-over-Ethernet (PoE) circuit 1012 isconnected between the network connector 1004 and the applicationconnector 1006 coupled to the network interface module 1002. The PoEcircuit 1012 comprises a transformer 1016 connected to communicationsignal pins 1004S of the network interface 1004.

An Ethernet physical layer (PHY) 1018 external to the network interfacemodule 1002 can be coupled to the transformer 1016 through theapplication interface 1006.

The Power-over-Ethernet (PoE) circuit 1012 can further comprise aPowered Ethernet Device (PD) controller 1020 coupled to power pins 1004Pof the network interface 1004.

In some embodiments, the Power-over-Ethernet (PoE) circuit 1012 canfurther comprise a Direct Current-Direct Current (DC-DC) power converter1022 connected between the PD controller 1020 and power pins 1010 of theapplication interface 1006.

Referring to FIG. 11, a schematic block diagram shows an embodiment of apowered network device, for example a network attached appliance 1192.In this case, the network attached appliance is a VOIP telephone.Network connector 1132 takes form of an Ethernet network connector, suchas RJ45 connector, and passes Ethernet signals to powerfeed circuitry1162 and PD controller 1140. Non-magnetic transformer and choke powerfeed circuitry 1162 separates the data signal and power signal. The datasignal is provided to network physical layer 1136. Network physicallayer 1136 couples to a network MAC to execute the network hardwarelayer. An application specific processor, such as VOIP processor 1194 orrelated processors, couples to the network MAC. Additionally, the VOIPtelephone processors and related circuitry (display 1196 and memory 1198and 1199) may be powered by power converter 1138 using power fed andseparated from the network signal by non-magnetic transformer and chokepowerfeed circuitry 1162. In other embodiments, other networkappliances, such as cameras, routers, printers and other like devicesare envisioned.

In some embodiments, a network device 1192 can be configured to receivemultiple power signals and data signals through a coupled network 1122.The network device 1192 comprises a network connector 1132 configured tophysically couple the network device 1192 to the network 1222 andreceive four twisted pairs that carry the power signals including, forexample a first power signal and a second power signal. The networkdevice 1192 further comprises an integrated circuit (IC) coupled to thenetwork connector 1132 which comprises an Ethernet physical layer (PHY)module 1136, a power management module 1136. Isolation capacitors can becoupled between the Ethernet PHY module 1136 and an application device1194 and an optical coupler can be coupled between the power managementmodule 1140 and the application device 1194. A direct connection moduleis coupled to the network connector 1132 and operative to pass thereceived data signal(s) to the Ethernet PHY 1136, sense a currentassociated with the twisted pairs, actively balance current associatedwith the twisted pairs, and pass the received plurality of power signalsto the power management module 1140 wherein the power management moduleis operative to at least partially power the network device 1192 fromthe received plurality of power signals.

Referring to FIG. 12, a schematic functional block diagram illustratesan embodiment of a network device in a configuration of a networkattached appliance 1292 including a power sourcing equipment (PSE)device. The network attached appliance is shown as a VoIP telephone.Network connector 1232 takes form of an Ethernet network connector, suchas RJ45 connector, and passes Ethernet signals to power feed circuitry1262 and PD controller 1240. Non-magnetic transformer and choke powerfeed circuitry 1262 separates the data signal and power signal. Anoptional connection to an external isolated power supply allows thenetwork attached device to be powered when insufficient power isavailable or when more power is required than can be provided over theEthernet connection. The data signal is provided to network physicallayer 1236. Network physical layer 1236 couples to a network MAC toexecute the network hardware layer. An application specific processor,such as VoIP processor 1294 or related processors, couples to thenetwork MAC. Additionally, the VoIP telephone processors and relatedcircuitry (display 1296 and memory 1298 and 1299) may be powered bypower converter 1238 using power fed and separated from the networksignal by non-magnetic transformer and choke power feed circuitry 1262.In other embodiments, other network appliances, such as cameras,routers, printers and other like devices are envisioned.

FIG. 12 is a functional block diagram of a specific network attached PSEdevice 1293. In this embodiment, PSE network device 1293 is an Ethernetrouter. Network connector 1232 may take the form of Ethernet networkconnector such as an RJ-45 connector, and is operable to distributeEthernet signals that include both power and data as combined by theintegrated circuits within PSE 1293. PSE 1293 includes an integratedcircuit 1266 which serves as a nonmagnetic transformer and chokecircuit.

The 1500 volt isolation between earth ground and the PSE network devicemay be achieved through various means. The data connections may becapacitively isolated, optically isolated or isolated using atransformer. The power connection is isolated using one or more isolatedpower supplies. Capacitors 1215, 1216 and optocoupler 1217 in FIG. 12are one example of this isolation.

The PSE devices may be a single port or multi-port. As a single portthis device can also be applied to a mid-span application. Data isprovided to Ethernet physical layer 1254 either from network devicesattached to network connector 1232 or data received from an externalnetwork via internet switch 1258 and an uplink. Ethernet switch 1258could be an application specific processor or related processors thatare operable to couple PSE 1293 via an uplink to an external network.

PSE devices may be integrated into various switches and routers forenterprise switching applications. However, in non-standard networkse.g. automotive etc., these PSE devices may be integrated intocontroller for the attached devices. In the case of multimedia orcontent distribution, these PSE devices may be incorporated into acontroller/set-top box that distributes content and power to attacheddevices.

Nonmagnetic transformer and choke circuitry 1266 receives data fromEthernet physical layer 1254. Additionally, power is supplied to thenonmagnetic transformer and choke circuitry 1266 from isolated powersupply 1297. In one embodiment this is a 48-volt power supply. However,this power distribution system may be applied to other powerdistribution systems, such as 110 volt systems as well. PSE controller1256 receives the power signal from isolated power supply 1297 and isoperable to govern the power signal content within the Ethernet signalsupplied by nonmagnetic transformer and choke circuitry 1266. Forexample, PSE controller 1256 may limit the Ethernet power produced bynonmagnetic transformer and choke circuitry 1266 based on therequirements of an attached PD. Thus PSE controller 1256 is operable toensure that attached network PDs are not overloaded and are given aproper power signal. Power supply 1297 also supplies as shown a powersignal to Ethernet PHY 1254, Ethernet switch 1258.

Isolated power supply 1297 may be attached to an AC power supply orother internal or external power supply in order to provide a powersignal to be distributed to network-attached devices that couple to PSE1293. PSE controller 1256 may determine, in accordance with IEEEstandard 802.3af, whether or not a network-attached device, in the caseof an Ethernet-attached device, is a device operable to receive powerfrom power supply equipment. When it is determined that an 802.3afcompliant PD is attached to the network, PSE controller 1256 may supplypower from power supply 1297 to nonmagnetic transformer and chokecircuitry 1266, which is then provided to the downstreamnetwork-attached device through network connectors 1232.

The 802.3 af Standard is intended to be fully compliant with allexisting non-line powered Ethernet systems. As a result, the PSE networkdevice is required to detect via a well defined procedure whether or notthe far end network attached device is POE compliant and classify theamount of needed power prior to applying power to the system. Maximumallowed voltage is 57 volts to stay within the SELV (Safety Extra LowVoltage) limits.

In order to be backward compatible with non-powered systems the DCvoltage applied will begin at a very low voltage and only begin todeliver power after confirmation that a POE device is present. Duringclassification the PSE network device applies a voltage between 14.5Vand 20.5V, and measures the current to determine the power class of thedevice.

The PSE network device enters a normal power supply mode afterdetermining that the PD is ready to receive power. At this point the 48Vsupply is connected to the Ethernet cable. During the normal powersupply mode, a maintain power signature is sensed by the PSE to continuesupplying power. The maximum current allowed is limited by the powerclass of the network attached device.

In some embodiments, a power source equipment (PSE) network device 1293operative to distribute a network power signal and a network data signalthrough a coupled network and comprises a network connector 1232configured to physically couple the PSE network device 1293 to thenetwork, and an integrated circuit (IC) coupled to the network connector1232 that further comprises a power feed circuit 1242 which exchangesdata signals with a network physical layer (PHY) module 1216, anEthernet switch 1282, and the network connector 1232. The integratedcircuit also isolates the network PHY module 1216 from the Ethernetswitch 1282, and passes the power signal to the network connector 1232as directed by a power source equipment (PSE) controller. The powersignal is received from an isolated power supply.

In some embodiments, power can be supplied from a power source equipment(PSE) network device 1293 with an Ethernet power signal fed through anEthernet network connection by producing the Ethernet power signal frompower supplied by an isolated power supply 1297 in an integrated circuit(IC) within the PSE network device 1293. The PSE network device 1293 isphysically coupled to the isolated power supply and physically coupledto an Ethernet network. An Ethernet data signal and the Ethernet powersignal are combined within the IC to produce an Ethernet signal. Groundisolation is provided for the Ethernet data signal and the Ethernetpower signal. The Ethernet signal is exchanged with at least oneEthernet network power device (PD) which is physically coupled to theEthernet network 1222 within the PSE network device 1293. The IC isisolated from the one or more Ethernet network power devices.

In various embodiments, a power source equipment (PSE) network device1293 can be operative to distribute an Ethernet power signal and anEthernet data signal through a coupled Ethernet network. Theillustrative PSE network device 1293 comprises an Ethernet networkconnector 1232 configured to physically couple the PSE network device1293 to the Ethernet network, a PSE controller, an Ethernet physicallayer (PHY) module 1216 configured to couple the PSE network device 1293to a multiport switch 1282 at an isolated interface 1225, 1226; and anintegrated circuit (IC). The IC is coupled to the Ethernet networkconnector 1232 that further comprises a power feed circuit 1242 which isconfigured to exchange Ethernet data signals with the Ethernet PHYmodule 1216 and the Ethernet connector 1232, supply a power signal froma power supply to the PSE network device 1293, and produce and pass theEthernet power signal to the Ethernet connector 1232 as directed by thePSE controller.

Although the description herein may focus and describe a system andmethod for coupling high bandwidth data signals and power distributionbetween the integrated circuit and cable that uses transformer-less ICswith particular detail to the IEEE 802.3af Ethernet standard, theconcepts may be applied in non-Ethernet applications and non-IEEE802.3af applications. Also, the concepts may be applied in subsequentstandards that supersede or complement the IEEE 802.3af standard.

Various embodiments of the depicted system may support solid state, andthus non-magnetic, transformer circuits operable to couple highbandwidth data signals and power signals with new mixed-signal ICtechnology, enabling elimination of cumbersome, real-estate intensivemagnetic-based transformers.

Typical conventional communication systems use transformers to performcommon mode signal blocking, 1500 volt isolation, and AC coupling of adifferential signature as well as residual lightning or electromagneticshock protection. The functions are replaced by a solid state or othersimilar circuits in accordance with embodiments of circuits and systemsdescribed herein whereby the circuit may couple directly to the line andprovide high differential impedance and low common mode impedance. Highdifferential impedance enables separation of the physical layer (PHY)signal from the power signal. Low common mode impedance enableselimination of a choke, allowing power to be tapped from the line. Thelocal ground plane may float to eliminate a requirement for 1500 voltisolation. Additionally, through a combination of circuit techniques andlightning protection circuitry, voltage spike or lightning protectioncan be supplied to the network attached device, eliminating anotherfunction performed by transformers in traditional systems orarrangements. The disclosed technology may be applied anywheretransformers are used and is not limited to Ethernet applications.

Specific embodiments of the circuits and systems disclosed herein may beapplied to various powered network attached devices or Ethernet networkappliances. Such appliances include, but are not limited to VoIPtelephones, routers, printers, and other similar devices.

The IEEE 802.3 Ethernet Standard, which is incorporated herein byreference, addresses loop powering of remote Ethernet devices (802.3af).Power over Ethernet (PoE) standard and other similar standards supportstandardization of power delivery over Ethernet network cables to powerremote client devices through the network connection. The side of linkthat supplies power is called Powered Supply Equipment (PSE). The sideof link that receives power is the Powered device (PD). Otherimplementations may supply power to network attached devices overalternative networks such as, for example, Home Phoneline Networkingalliance (HomePNA) local area networks and other similar networks.HomePNA uses existing telephone wires to share a single networkconnection within a home or building. In other examples, devices maysupport communication of network data signals over power lines.

In various configurations described herein, a magnetic transformer ofconventional systems may be eliminated while transformer functionalityis maintained. Techniques enabling replacement of the transformer may beimplemented in the form of integrated circuits (ICs) or discretecomponents.

FIG. 1A is a schematic block diagram that illustrates a high levelexample embodiment of devices in which power is supplied separately tonetwork attached client devices 112 through 116 that may benefit fromreceiving power and data via the network connection. The devices areserviced by a local area network (LAN) switch 110 for data. Individualclient devices 112 through 116 have separate power connections 118 toelectrical outlets 120. FIG. 1B is a schematic block diagram thatdepicts a high level example embodiment of devices wherein a switch 110is a power supply equipment (PSE)-capable power-over Ethernet (PoE)enabled LAN switch that supplies both data and power signals to clientdevices 112 through 116. Network attached devices may include a VoiceOver Internet Protocol (VOIP) telephone 112, access points, routers,gateways 114 and/or security cameras 116, as well as other known networkappliances. Network supplied power enables client devices 112 through116 to eliminate power connections 118 to electrical outlets 120 asshown in FIG. 1A. Eliminating the second connection enables the networkattached device to have greater reliability when attached to the networkwith reduced cost and facilitated deployment.

Referring to FIG. 2, a functional block diagram depicts an embodiment ofa network device 200 including a T-Less Connect™ solid-statetransformer. The illustrative network device comprises a power potentialrectifier 202 adapted to conductively couple a network connector 232 toan integrated circuit 270, 272 that rectifies and passes a power signaland data signal received from the network connector 232. The powerpotential rectifier 202 regulates a received power and/or data signal toensure proper signal polarity is applied to the integrated circuit 270,272.

The network device 200 is shown with the power sourcing switch 270sourcing power through lines 1 and 2 of the network connector 232 incombination with lines 3 and 6.

In some embodiments, the power potential rectifier 202 is configured tocouple directly to lines of the network connector 232 and regulate thepower signal whereby the power potential rectifier 202 passes the datasignal with substantially no degradation.

In some configuration embodiments, the network connector 232 receivesmultiple twisted pair conductors 204, for example twisted 22-26 gaugewire. Any one of a subset of the twisted pair conductors 204 can forwardbias to deliver current and the power potential rectifier 202 canforward bias a return current path via a remaining conductor of thesubset.

FIG. 2 illustrates the network interface 200 including a network powereddevice (PD) interface and a network power supply equipment (PSE)interface, each implementing a non-magnetic transformer and chokecircuitry. A powered end station 272 is a network interface thatincludes a network connector 232, non-magnetic transformer and chokepower feed circuitry 262, a network physical layer 236, and a powerconverter 238. Functionality of a magnetic transformer is replaced bycircuitry 262. In the context of an Ethernet network interface, networkconnector 232 may be a RJ45 connector that is operable to receivemultiple twisted wire pairs. Protection and conditioning circuitry maybe located between network connector 232 and non-magnetic transformerand choke power feed circuitry 262 to attain surge protection in theform of voltage spike protection, lighting protection, external shockprotection or other similar active functions. Conditioning circuitry maybe a diode bridge or other rectifying component or device. A bridge orrectifier may couple to individual conductive lines 1-8 contained withinthe RJ45 connector. The circuits may be discrete components or anintegrated circuit within non-magnetic transformer and choke power feedcircuitry 262.

In an Ethernet application, the IEEE 802.3af standard (PoE standard)enables delivery of power over Ethernet cables to remotely powerdevices. The portion of the connection that receives the power may bereferred to as the powered device (PD). The side of the link thatsupplies power is called the power sourcing equipment (PSE).

In the powered end station 272, conductors 1 through 8 of the networkconnector 232 couple to non-magnetic transformer and choke power feedcircuitry 262. Non-magnetic transformer and choke power feed circuitry262 may use the power feed circuit and separate the data signal portionfrom the power signal portion. The data signal portion may then bepassed to the network physical layer (PHY) 236 while the power signalpasses to power converter 238.

If the powered end station 272 is used to couple the network attacheddevice or PD to an Ethernet network, network physical layer 236 may beoperable to implement the 10 Mbps, 100 Mbps, and/or 1 Gbps physicallayer functions as well as other Ethernet data protocols that may arise.The Ethernet PHY 236 may additionally couple to an Ethernet media accesscontroller (MAC). The Ethernet PHY 236 and Ethernet MAC when coupled areoperable to implement the hardware layers of an Ethernet protocol stack.The architecture may also be applied to other networks. If a powersignal is not received but a traditional, non-power Ethernet signal isreceived the nonmagnetic power feed circuitry 262 still passes the datasignal to the network PHY.

The power signal separated from the network signal within non-magnetictransformer and choke power feed circuit 262 by the power feed circuitis supplied to power converter 238. Typically the power signal receiveddoes not exceed 57 volts SELV (Safety Extra Low Voltage). Typicalvoltage in an Ethernet application is 48-volt power. Power converter 238may then further transform the power as a DC to DC converter to provide1.8 to 3.3 volts, or other voltages specified by many Ethernet networkattached devices.

Power-sourcing switch 270 includes a network connector 232, Ethernet ornetwork physical layer 254, PSE controller 256, non-magnetic transformerand choke power supply circuitry 266, and possibly a multiple-portswitch. Transformer functionality is supplied by non-magnetictransformer and choke power supply circuitry 266. Power-sourcing switch270 may be used to supply power to network attached devices. Powered endstation 272 and power sourcing switch 270 may be applied to an Ethernetapplication or other network-based applications such as, but not limitedto, a vehicle-based network such as those found in an automobile,aircraft, mass transit system, or other like vehicle. Examples ofspecific vehicle-based networks may include a local interconnect network(LIN), a controller area network (CAN), or a flex ray network. All maybe applied specifically to automotive networks for the distribution ofpower and data within the automobile to various monitoring circuits orfor the distribution and powering of entertainment devices, such asentertainment systems, video and audio entertainment systems often foundin today's vehicles. Other networks may include a high speed datanetwork, low speed data network, time-triggered communication on CAN(TTCAN) network, a J1939-compliant network, ISO11898-compliant network,an ISO11519-2-compliant network, as well as other similar networks.Other embodiments may supply power to network attached devices overalternative networks such as but not limited to a HomePNA local areanetwork and other similar networks. HomePNA uses existing telephonewires to share a single network connection within a home or building.Alternatively, embodiments may be applied where network data signals areprovided over power lines.

Non-magnetic transformer and choke power feed circuitry 262 and 266enable elimination of magnetic transformers with integrated systemsolutions that enable an increase in system density by replacingmagnetic transformers with solid state power feed circuitry in the formof an integrated circuit or discreet component.

In some embodiments, non-magnetic transformer and choke power feedcircuitry 262, network physical layer 236, power distribution managementcircuitry 254, and power converter 238 may be integrated into a singleintegrated circuit rather than discrete components at the printedcircuit board level. Optional protection and power conditioningcircuitry may be used to interface the integrated circuit to the networkconnector 232.

The Ethernet PHY may support the 10/100/1000 Mbps data rate and otherfuture data networks such as a 10000 Mbps Ethernet network. Non-magnetictransformer and choke power feed circuitry 262 supplies line power minusthe insertion loss directly to power converter 238, converting powerfirst to a 12V supply then subsequently to lower supply levels. Thecircuit may be implemented in any appropriate process, for example a0.18 or 0.13 micron process or any suitable size process.

Non-magnetic transformer and choke power feed circuitry 262 mayimplement functions including IEEE 802.3.af signaling and loadcompliance, local unregulated supply generation with surge currentprotection, and signal transfer between the line and integrated EthernetPHY. Since devices are directly connected to the line, the circuit maybe implemented to withstand a secondary lightning surge.

For the power over Ethernet (PoE) to be IEEE 802.3af standard compliant,the PoE may be configured to accept power with various power feedingschemes and handle power polarity reversal. A rectifier, such as a diodebridge, a switching network, or other circuit, may be implemented toensure power signals having an appropriate polarity are delivered tonodes of the power feed circuit. Any one of the conductors 1, 4, 7 or 3of the network RJ45 connection can forward bias to deliver current andany one of the return diodes connected can forward bias to form a returncurrent path via one of the remaining conductors. Conductors 2, 5, 8 and4 are connected similarly.

Non-magnetic transformer and choke power feed circuitry 262 applied toPSE may take the form of a single or multiple port switch to supplypower to single or multiple devices attached to the network. Powersourcing switch 270 may be operable to receive power and data signalsand combine to communicate power signals which are then distributed viaan attached network. If power sourcing switch 270 is a gateway orrouter, a high-speed uplink couples to a network such as an Ethernetnetwork or other network. The data signal is relayed via network PHY 254and supplied to non-magnetic transformer and choke power feed circuitry266. PSE switch 270 may be attached to an AC power supply or otherinternal or external power supply to supply a power signal to bedistributed to network-attached devices that couple to power sourcingswitch 270. Power controller 256 within or coupled to non-magnetictransformer and choke power feed circuitry 266 may determine, inaccordance with IEEE standard 802.3af, whether a network-attached devicein the case of an Ethernet network-attached device is a device operableto receive power from power supply equipment. When determined that anIEEE 802.3af compliant powered device (PD) is attached to the network,power controller 256 may supply power from power supply to non-magnetictransformer and choke power feed circuitry 266, which is sent to thedownstream network-attached device through network connectors, which inthe case of the Ethernet network may be an RJ45 receptacle and cable.

IEEE 802.3af Standard is to fully comply with existing non-line poweredEthernet network systems. Accordingly, PSE detects via a well-definedprocedure whether the far end is PoE compliant and classify sufficientpower prior to applying power to the system. Maximum allowed voltage is57 volts for compliance with SELV (Safety Extra Low Voltage) limits.

For backward compatibility with non-powered systems, applied DC voltagebegins at a very low voltage and only begins to deliver power afterconfirmation that a PoE device is present. In the classification phase,the PSE applies a voltage between 14.5V and 20.5V, measures the currentand determines the power class of the device. In one embodiment thecurrent signature is applied for voltages above 12.5V and below 23Volts. Current signature range is 0-44 mA.

The normal powering mode is switched on when the PSE voltage crosses 42Volts where power MOSFETs are enabled and the large bypass capacitorbegins to charge.

A maintain power signature is applied in the PoE signature block—aminimum of 10 mA and a maximum of 23.5 kohms may be applied for the PSEto continue to feed power. The maximum current allowed is limited by thepower class of the device (class 0-3 are defined). For class 0, 12.95 Wis the maximum power dissipation allowed and 400 ma is the maximum peakcurrent. Once activated, the PoE will shut down if the applied voltagefalls below 30V and disconnect the power MOSFETs from the line.

Power feed devices in normal power mode provide a differential opencircuit at the Ethernet signal frequencies and a differential short atlower frequencies. The common mode circuit presents the capacitive andpower management load at frequencies determined by the gate controlcircuit.

Terms “substantially”, “essentially”, or “approximately”, that may beused herein, relate to an industry-accepted tolerance to thecorresponding term. Such an industry-accepted tolerance ranges from lessthan one percent to twenty percent and corresponds to, but is notlimited to, component values, integrated circuit process variations,temperature variations, rise and fall times, and/or thermal noise. Theterm “coupled”, as may be used herein, includes direct coupling andindirect coupling via another component, element, circuit, or modulewhere, for indirect coupling, the intervening component, element,circuit, or module does not modify the information of a signal but mayadjust its current level, voltage level, and/or power level. Inferredcoupling, for example where one element is coupled to another element byinference, includes direct and indirect coupling between two elements inthe same manner as “coupled”.

While the present disclosure describes various embodiments, theseembodiments are to be understood as illustrative and do not limit theclaim scope. Many variations, modifications, additions and improvementsof the described embodiments are possible. For example, those havingordinary skill in the art will readily implement the steps necessary toprovide the structures and methods disclosed herein, and will understandthat the process parameters, materials, and dimensions are given by wayof example only. The parameters, materials, and dimensions can be variedto achieve the desired structure as well as modifications, which arewithin the scope of the claims. Variations and modifications of theembodiments disclosed herein may also be made while remaining within thescope of the following claims. For example, various aspects or portionsof a network interface are described including several optionalimplementations for particular portions. Any suitable combination orpermutation of the disclosed designs may be implemented.

1. A network device comprising: a network attached appliance comprising: a housing; an application processor contained within the housing; and a connector module contained within the housing and configured to couple the application processor to a network, the connector module comprising: a network connector coupled to the connector module in a configuration that transfers power and communication signals; an application connector coupled to the connector module and configured for coupling to the application processor; and a Power-over-Ethernet (PoE) circuit coupled between the network connector and the application connector.
 2. The network device according to claim 1 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Device (iPED) comprising: a non-magnetic transformer and choke circuit integrated into the iPED and coupled between communication signal pins of the network interface and the application interface; a Powered Ethernet Device (PD) controller integrated into the iPED and coupled to power pins of the network interface; and a Direct Current-Direct Current (DC-DC) power converter integrated into the iPED and coupled between the PD controller and power pins of the application interface.
 3. The network device according to claim 2 further comprising: the integrated Powered Ethernet Device (iPED) further comprising: isolation capacitors coupled between the non-magnetic transformer and choke circuit and the application interface; and at least one optical coupler coupled between the Powered Ethernet Device (PD) and the application interface.
 4. The network device according to claim 1 further comprising: the network attached appliance further comprising: an Ethernet physical layer (PHY) coupled between the application interface and the application processor, the Ethernet PHY coupled to the application processor by a SMII interface and a Management Data Input/Output (MDIO) interface.
 5. The network device according to claim 1 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Device (iPED) comprising: a non-magnetic transformer and choke circuit integrated into the iPED and coupled between communication signal pins of the network interface and the application interface; an Ethernet physical layer (PHY) integrated into the iPED and coupled between the non-magnetic transformer and choke circuit and the application interface, the Ethernet PHY coupled to the application interface by a SMII interface and a Management Data Input/Output (MDIO) interface; a Powered Ethernet Device (PD) controller integrated into the iPED and coupled to power pins of the network interface; and a Direct Current-Direct Current (DC-DC) power converter integrated into the iPED and coupled between the PD controller and power pins of the application interface.
 6. The network device according to claim 1 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Device (iPED) comprising: an isolated Ethernet physical layer (PHY) integrated into the iPED and coupled to the application interface by a SMII interface and a Management Data Input/Output (MDIO) interface; a Powered Ethernet Device (PD) controller integrated into the iPED and coupled to power pins of the network interface; and an isolated Direct Current-Direct Current (DC-DC) power converter integrated into the iPED and coupled between the PD controller and power pins of the application interface.
 7. The network device according to claim 6 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Device (iPED) further comprising: an autotransformer integrated into the iPED and coupled between communication signal pins of the network interface and the application interface.
 8. The network device according to claim 7 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Device (iPED) further comprising: isolation capacitors coupled to the autotransformer and integrated into the iPED coupled between communication signal pins of the network interface and the application interface.
 9. The network device according to claim 6 further comprising: the isolated Ethernet physical layer (PHY) further comprising: isolation capacitors coupled to the SMII interface and the MDIO interface.
 10. The network device according to claim 6 further comprising: an isolation barrier formed by the isolated Ethernet physical layer (PHY) and the isolated Direct Current-Direct Current (DC-DC) power converter isolating the network interface and the application interface.
 11. A network device comprising: a network interface module comprising: a network connector coupled to the network interface module in a configuration that transfers power and communication signals; an application connector coupled to the network interface module; and a Power-over-Ethernet (PoE) circuit coupled between the network connector and the application connector, the PoE circuit comprising: a transformer coupled to communication signal pins of the network interface.
 12. The network device according to claim 11 further comprising: an Ethernet physical layer (PHY) external to the network interface module coupled to the transformer through the application interface.
 13. The network device according to claim 11 further comprising: the Power-over-Ethernet (PoE) circuit further comprising: a Powered Ethernet Device (PD) controller coupled to power pins of the network interface.
 14. The network device according to claim 11 further comprising: the Power-over-Ethernet (PoE) circuit further comprising: a Direct Current-Direct Current (DC-DC) power converter coupled between the PD controller and power pins of the application interface.
 15. A network device comprising: a power sourcing equipment appliance comprising: a housing; an Ethernet switch contained within the housing; an isolated power supply contained within the housing; and a connector module contained within the housing and configured to couple the Ethernet switch and the isolated power supply to a network, the connector module comprising: a network connector coupled to the connector module in a configuration that transfers power and communication signals; an application connector coupled to the connector module and comprising serial media independent interface (SMII) pins and power pins; and a Power-over-Ethernet (PoE) circuit coupled between the network connector and the application connector comprising: an integrated Powered Ethernet Source (iPES) comprising: an isolated Ethernet physical layer (PHY) integrated into the iPES coupled to the application interface by a SMII interface and a Management Data Input/Output (MDIO) interface; and a Power Sourcing Equipment (PSE) controller coupled to power feed pins of the application interface.
 16. The network device according to claim 15 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Source (iPES) further comprising: an autotransformer integrated into the iPED and coupled between communication signal pins of the network interface and the application interface.
 17. The network device according to claim 16 further comprising: the Power-over-Ethernet (PoE) circuit comprising: an integrated Powered Ethernet Source (iPES) further comprising: isolation capacitors coupled to the autotransformer and integrated into the iPES coupled between communication signal pins of the network interface and the application interface.
 18. The network device according to claim 15 further comprising: the isolated Ethernet physical layer (PHY) further comprising: isolation capacitors coupled to the SMII interface and the MDIO interface.
 19. The network device according to claim 15 further comprising: a Buck converter integrated into the integrated Powered Ethernet Source (iPES) and coupled to a power line supplying the isolated Ethernet physical layer (PHY) from the isolated power supply.
 20. The network device according to claim 15 further comprising: an isolation barrier formed by the isolated Ethernet physical layer (PHY) and the isolated Direct Current-Direct Current (DC-DC) power converter isolating the network interface and the application interface.
 21. A network device configured to receive a plurality of power signals and data signals through a coupled network comprising: a network connector configured to physically couple the network device to the network and receive four twisted pairs that carry the plurality of power signals, wherein the plurality of power signals comprise a first power signal and a second power signal; and an integrated circuit (IC) coupled to the network connector and comprising: an Ethernet physical layer (PHY) module; a power management module; isolation capacitors coupled between the Ethernet PHY module and an application device; an optical coupler coupled between the power management module and the application device; and a direct connection module coupled to the network connector and operative to: pass the received data signal(s) to the Ethernet PHY; sense a current associated with the twisted pairs; actively balance current associated with the twisted pairs; and pass the received plurality of power signals to the power management module wherein the power management module is operative to at least partially power the network device from the received plurality of power signals.
 22. A power source equipment (PSE) network device operative to distribute a network power signal and a network data signal through a coupled network comprising: a network connector configured to physically couple the PSE network device to the network; and an integrated circuit (IC) coupled to the network connector that further comprises a power feed circuit operative to: exchange data signals with a network physical layer (PHY) module, Ethernet switch, and the network connector; isolate the network PHY module from the Ethernet switch; and pass the power signal to the network connector as directed by a power source equipment (PSE) controller, wherein the power signal is received from an isolated power supply.
 23. A method for supplying power from a power source equipment (PSE) network device with an Ethernet power signal fed through an Ethernet network connection comprising: producing the Ethernet power signal from power supplied by an isolated power supply in an integrated circuit (IC) within the PSE network device; physically coupling the PSE network device to the isolated power supply; physically coupling the PSE network device to an Ethernet network; combining within the IC an Ethernet data signal and the Ethernet power signal to produce an Ethernet signal; providing ground isolation for the Ethernet data signal and the Ethernet power signal; exchanging the Ethernet signal with at least one Ethernet network power device (PD) physically coupled to the Ethernet network within the PSE network device; and isolating the IC from the at least one Ethernet network power device.
 24. A power source equipment (PSE) network device operative to distribute an Ethernet power signal and an Ethernet data signal through a coupled Ethernet network comprising: an Ethernet network connector configured to physically couple the PSE network device to the Ethernet network; a PSE controller; an Ethernet physical layer (PHY) module configured to couple the PSE network device to a multiport switch at an isolated interface; and an integrated circuit (IC) coupled to the Ethernet network connector that further comprises a power feed circuit configured to: exchange Ethernet data signals with the Ethernet PHY module and the Ethernet connector; supply a power signal from a power supply to the PSE network device; and produce and pass the Ethernet power signal to the Ethernet connector as directed by the PSE controller. 